Empirical Rule for Statistics

What percent of people within 1 standard deviation of the mean?

• 99.7

• 34

• 68

• 95

What percent of people within 2 standard deviations of the mean?

• 99.7

• 34

• 68

• 95

What percent of people within 3 standard deviations of the mean?

• 99.7

• 34

• 68

• 95

What percent of people outside of 3 standard deviations of the mean?

• 13

• .15

• 157

• .3

At a local high school, GPA's are normally distributed with a mean of 2.9 and standard deviation of 0.6. What percentage of students at the high school have a GPA between 2.3 and 3.5?

• 68%
• 99.7%
• 95%
• 84%

At a local high school, GPA's are normally distributed with a mean of 2.9 and standard deviation of 0.6. What is the GPA of the highest 2.5% of the students?

• 4.1 
• 4.1 or higher
• 4.7
• 4.5 or higher

The mean life of a tire is 30,000 km. The standard deviation is 2000 km.

Then, 68% of all tires will have a life between ___________ km and __________ km.

•  28,000 km and 32,000 km.
• 24,000 km and 34,000 km.
• 26,000 km and 34,000 km.
• 27,000 km and 31,000 km.

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days.

About what percent of the products last between 12 and 15 days?

• 68%
• 34%
• 16%
• 2.5%

Which interval shows 95% of the data given a mean of 15 and a standard deviation of 3? 

• 9 to 21
• 12 to 18
• 6 to 24
• 13 to 16

Which interval shows 68% of the data given a mean of 15 and a standard deviation of 3? 

• 9 to 21
• 12 to 18
• 6 to 24
• 13 to 16